The STICH Myocardial Revascularization Hypothesis completed enrollment of 1212 subjects in whom the responsible physicians were at equipoise regarding the benefits of myocardial revascularization in May 2007. Patients were randomized 1:1 to continuing optimal medical therapy (MED) with or without CABG. With this fixed sample size, approximately 400 patients need to meet the primary endpoint of all-cause mortality to achieve 90% power to test whether CABG leads to the hypothesized mortality reduction of 25% over MED. Surviving STICH subjects will return for a final visit with an average follow-up of 5 years and all investigative sites will cease patient follow-up activities by the end of 2010 as per protocol. Database closure, un-blinding of investigators and the reporting of 5 year results will follow subsequently. STICH subjects represent the first ever CAD cohort with LVSD randomized to a strategy of medical therapy alone or with concurrent coronary revascularization and will begin to fill a deep knowledge gap which exists for these high-risk patients. Upon randomization, they underwent a battery of baseline and follow-up testing overseen by 5 core laboratories for ECHO, RN myocardial perfusion and viability, CMR, neurohormonal, cytokine and genetic blood testing (NCG), and economics and quality of life (EQoL). We propose to take advantage of the opportunities that the surviving STICH patients present to the medical community and follow these patients for an additional 5 years. We will thereby acquire critically important longer-term (10-year average) information on patients with HF and LVSD treated with optimal medical therapy (MED) with and without coronary bypass graft (CABG). This STICH Extension Study (referred to in the proposal as STICHES) will capitalize on a unique and already exceptionally well-characterized cohort of patients with LVSD, HF and CAD amenable to CABG to address the following specific aims: 1. To determine whether CABG with MED improves 10 year survival compared to MED alone and how treatment-related outcome differences seen at 5 years vary over time. 2. To determine whether CABG with MED leads to differences in health outcomes including functional status and symptoms compared to MED alone at 10 years among important subgroups defined by baseline clinical status, symptoms, coronary anatomy, functional status, noninvasive measures of myocardial ischemia and viability and/or genotype. 3. To quantify the relative, incremental predictive value of baseline non-invasive cardiac imaging on long-term treatment-dependent results (relative to the short and intermediate-term). 4. To determine whether CABG with MED leads to changes in cardiac morphology, function and hemodynamics over time (4 and 24 months) compared to MED alone and to define how these changes relate to 10 year health outcomes. PUBLIC HEALTH RELEVANCE: Over 5 million patients have HF in the Unites States with the majority having associated CAD. Many undergo non-invasive and invasive cardiovascular imaging followed by coronary revascularization at a significant personal and societal cost. The results of the STICHES study will help guide patient selection and better inform whether these strategies lead to better health outcomes for these high-risk individuals and for the society as a whole.